Process of zine pressure casting non cyanogen alkaline immersion plating copper

An alkaline and casting technology, applied in the field of cyanide-free alkaline dipping metal plating process and cyanide-free alkaline dipping copper plating of zinc die castings, can solve the problems of inability to use zinc die castings, achieve low cost, eliminate pollution, and be easy to use. The effect of promoting the application

Inactive Publication Date: 2007-07-18
GUANGZHOU UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the dissolution of zinc die castings in acid, all the above copper immersion and copper alloy processes can only be used for the acid process of steel workpieces, and cannot be used for zinc die castings

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Zinc die castings are processed through the following four processes:

[0021] (1) Wax removal for zinc die castings takes 8 minutes, chemical degreasing takes 10 minutes, cathodic electrolytic degreasing takes 2 minutes, and weak etching takes 0.5 minutes.

[0022] (2) After the zinc die castings pretreated in step (1) are washed with water, they are immersed in a cyanide-free copper leaching solution for 3.5 minutes at 25°C. The cyanide-free copper leaching solution contains CuSO with a concentration of 5g / l. 4 .5H 2 O, concentration is the sodium citrate that the HEDP of 48g / l and concentration are 15g / l, and the pH of cyanide-free copper leaching solution is 10, and this operation also can finish with barrel plating mode.

[0023] (3) After the zinc die-casting parts treated in step (2) are taken out and washed with water, citrate copper plating is carried out in a cyanide-free alkaline plating solution, and the citrate copper plating solution is electroplated for ...

Embodiment 2

[0027] (1) Zinc die castings are dewaxed for 6 minutes, chemical degreasing for 8 minutes, cathodic electrolytic degreasing for 3 minutes, and weak etching for 1 minute.

[0028] (2) After the zinc die-casting parts pretreated in step (1) are washed with water, they are rack-plated and immersed in a cyanide-free copper immersion solution for 15 minutes at 15°C. The pH of the cyanide-free copper immersion solution is 11, and its composition and content as follows:

[0029] Copper nitrate 80g / l

[0030] Sodium citrate 100g / l

[0031] Sodium Gluconate 50g / l

[0032] OP-10 2g / l

[0033] (3) The zinc die-casting parts treated in step (2) were taken out and washed with water, and then copper-plated in the HEDP system in a cyanide-free alkaline plating solution, and the copper was plated in the HEDP system for 6 minutes.

[0034] (4) Follow-up electroplating, specifically bright acid copper plating for 12 minutes, bright nickel plating for 6 minutes, and imitation gold plating fo...

Embodiment 3

[0037] (1) Zinc die castings are dewaxed for 12 minutes, chemical degreasing for 5 minutes, cathodic electrolytic degreasing for 3 minutes, and weak etching for 0.8 minutes.

[0038] (2) After the zinc die castings pretreated in step (1) are washed with water, they are barrel-plated and immersed in a cyanide-free copper immersion solution for 5 seconds at 60°C. The pH of the cyanide-free copper immersion solution is 13, and its composition and content as follows:

[0039] CuSO 4 .5H 2 O 0.1g / l

[0040] HEDP 1g / l

[0041] Sodium citrate 25g / l

[0042] ZnSO 7 .7H 2 O 8g / l

[0043] Ethylenethiourea 0.001g / l

[0044] (3) After the zinc die-casting parts treated in step (2) are taken out and washed with water, carry out pyrophosphate copper plating in a cyanide-free alkaline plating solution for 7 minutes.

[0045] (4) Follow-up electroplating, specifically bright acid copper plating for 8 minutes, bright nickel plating for 6 minutes, and imitation gold plating for 2 minut...

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PUM

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Abstract

The cyanide-free alkaline copper dip plating process for die cast zinc part includes the following steps: dewaxing die cast zinc part, deoiling, soaking in alkaline immersion liquid at 15-60 deg.c and pH 7.5-13.0 for 5 sec to 15 min to form replacing copper layer. The alkaline immersion liquid contains two-valent copper ion, and one or several kinds of inorganic or organic complexing agent selected from pyrophosphoric acid, tartaric acid, citric acid, gluconic acid, EDTA and HEDP acid radical ion a in the concentration of 1-150 g/L. The process of the present invention may be used to replace cyanide copper plating to form copper coating with high adhesion force without cyanide pollution.

Description

technical field [0001] The invention relates to an immersion-plating process, in particular to a cyanide-free alkaline immersion-plating metal process, in particular to a cyanide-free alkaline immersion copper plating method for zinc die castings. Background technique [0002] Copper-nickel-chromium, copper-nickel-imitation gold or copper-multilayer nickel-chromium electroplating process is a combination of electroplating processes with a wide range of applications. The underlying copper in the above process combinations must be obtained by cyanide electroplating. This is because the plated workpiece is made of metallic iron, which is very active. Only in the cyanide plating solution will it not have a substitution reaction with copper and affect the binding force. . Therefore, the electroplating industry consumes a large amount of cyanide every year. Cyanide is a highly toxic substance, which not only causes physical harm to operators, but also pollutes the environment. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23C28/00C23C22/05C25D3/00
Inventor 袁国伟于欣伟陈姚
Owner GUANGZHOU UNIVERSITY
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